IS ROSS MIRAGE OR FUTURE ACE FOR PADRES?

Change of scenery

Tyson Ross endured a frustrating season last year in Oakland. In San Diego, he has been vastly improved, albeit in a limited sample size. The following is a comparison of his numbers as a starter:

Year GS IP ERA WHIP K/9 BB/9 BAA

2012 13 68.1 6.45 1.76 5.4 4.2 .322

2013 9 54.1 2.48 1.09 8.9 3.6 .193

Who is Tyson Ross?

Is he the tall right-hander with the wipeout slider who recently compiled the best five-start stretch of his young career, and one of the best by any pitcher this season?

Or is he the tall right-hander who failed to rein in his fastball Tuesday night, as he did time and again in a failed experiment in Oakland?

The answer likely lies somewhere in between — somewhere, the Padres believe, closer to the first Ross, the one with the burgeoning command and that wipeout slider. Five brilliant starts out of six, after all, is an ace’s ratio.

“He can be a dominant pitcher in the big leagues,” said Padres pitching coach Darren Balsley.

Can be. Should be, with his stuff. But will he be?

It’s still too early to tell, but the signs are there. Ross has been one of the few, emergent lights in a season that long ago dimmed.

Since rejoining the Padres’ rotation after the All-Star break — a development delayed by an April injury to his non-throwing shoulder — Ross has put together an eye-opening run of success. Before he allowed a season-high four earned runs in Tuesday’s loss to the Pirates, the results of the previous five starts had offered a tantalizing glimpse of the 26-year-old’s potential: 34 innings pitched, 36 strikeouts, 10 walks, five runs allowed, and an opponents’ batting average of .149.

Even after Tuesday’s hiccup, over nine starts this season, Ross has a 2.48 ERA with 54 strikeouts in 54 1/3 innings.

“I can’t say I’m surprised,” Ross said last week. “I think if you go out there expecting anything less than to do well, you’re really just setting yourself up for failure.”

A quietly confident presence in the clubhouse, Ross experienced a parade of letdowns last season with his hometown team, the Oakland Athletics. He went 2-11 and posted a 6.50 ERA. In 73 1/3 innings, he struck out just 46 batters. He walked nearly as many.

In between, though, he left an impression on the Padres, allowing just one hit over six innings in a win over San Diego last June.

“I’d just seen him the one game against us,” Balsley said, “and he almost threw a no-hitter. We knew coming in he had great stuff.”

The Padres took a flyer on Ross’ considerable, if unharnessed, talent last November, acquiring Ross and infielder A.J. Kirby-Jones from Oakland for infielder Andy Parrino and left-hander Andrew Werner.

Under the tutelage of Balsley, Ross has looked like GM Josh Byrne’s best offseason acquisition. Since the All-Star break, Ross has walked just 12 batters in 40 1/3 innings. He is spotting his mid-90s fastball down and away to right-handers. He is mixing in an emerging change-up.

According to FanGraphs, his swinging strike rate of 10.3 percent is the highest of his career, up from 6.3 percent last season.

“The slider has been really devastating,” said Padres manager Bud Black. “That’s what a lot of opposing clubs are talking about, the slider.”

Ross reaches back to spring training to pinpoint the origin of his breakthrough. Balsley prescribed a “step-through drill” there, the idea being to sync Ross’ front foot hitting the ground with the moment his arm went up.

“He had me walking into throws off the mound and just got the timing synced up right,” said Ross, who despite standing 6-foot-6 has the shortest stride length of any Padres pitcher. “That was always my problem, having the leverage just a little bit off with my timing. But we figured out a way to get it all in sync, and everything’s just flowed from there.”

Ross’ growth includes a marked improvement against left-handed batters, who hit .356 off him in 149 at-bats last season.

In 148 at-bats this year, lefties are hitting just .230 against him.

Such success has imbued Ross with the confidence of a big-league starter, one who should figure prominently into the Padres’ rotation in 2014. The sample size remains small, but it appears the intangibles are beginning to catch up with the physical tools.

“His work ethic is so good, his focus is so good when he throws our side sessions and our bullpens,” Balsley said. “Each time he goes up there he is learning how good he can be.

“When you realize that you’re doing well and you can get that much better, you work harder and you have a higher ceiling.”